Welding up Front Differential for Dirt Racing - Racing Forum

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Welding up Front Differential for Dirt Racing
Sunday, May 14, 2006 3:24 PM
I was wondering where to find out how to Weld the front end up for dirt track racing. I have a 95 sunfire with the 3 speed auto. I am not getting very good traction while corning right now. Any help would be appreciated.

Re: Welding up Front Differential for Dirt Racing
Sunday, May 14, 2006 3:30 PM
u mean like how on a RWD car you can weld the spider gears a certain way and make it a posi diff?



i wouldnt suggest doing that on a FWD car ever, or on a RWD car.


-Borsty
Re: Welding up Front Differential for Dirt Racing
Sunday, May 14, 2006 3:38 PM
It is not a car for the street. It is a stripped down caged dirt track car. I have welded the rearends in pintos and a full size buick before to run in demolition derbys. They all held up fine. Just wondering if was the same. I don't know anything about front wheel drives...
Re: Welding up Front Differential for Dirt Racing
Sunday, May 14, 2006 7:04 PM
yeah, welding a fwd diff on a car that needs to turn is NOT a good idea. on a rwd car its completely different because you can spin the rear tires to turn (especially on dirt) but I think you'd be better getting an actual LSD for it. Since the front wheels have to turn to provide steering, if you weld the diff, the unequal loading on the gears and the weld between when you turn is going to break even the best welding job. How the heck do you dirt race a FWD anyway? understeer + lose surface = no fun




Arrival Blue 04 LS Sport
Eco
Turbo
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'Nuff said
Re: Welding up Front Differential for Dirt Racing
Sunday, May 14, 2006 10:29 PM
Saturday was my first trip to the track. It was fun, just want to do better. All I did was go into the corners hard hit the brake, crank the wheel and not let off the gas. I just was not getting any traction. Where do I get a LSD for the automatic? Are they expensive? Not wanting to spend a lot of money. That is why I asked about welding. I talked to a couple of guys that said they had their fronts welded up. Made it come off the corners better.
Re: Welding up Front Differential for Dirt Racing
Monday, May 15, 2006 11:28 AM
we've got a welded diff in our drag car (96 5 spd Z24)....... the only thing that brakes when we turn is axles




SPD RCR Z - '02 Z24 420whp
SLO GOAT - '04 GTO 305whp
W41 BOI - '78 Buick Opel Isuzu W41 Swap

Re: Welding up Front Differential for Dirt Racing
Monday, May 15, 2006 4:44 PM
aint that the truth/\/\/\/\/\/\/ now if we could get my car to do the same thing that would be great!!!!!!!!!!!!!



Re: Welding up Front Differential for Dirt Racing
Monday, May 15, 2006 7:15 PM
Yes, you can weld up the spider gears in the 3T40(3 SP). Just weld the spider gears to the side gears the same as a RWD diff. Your best bet to get the car to turn in better and protect the axles and diff,will be to put some stagger in the front tires, if the rules permit different sized tires. The amount of stagger will depend on then track lay out, what size tires you have and you tire pressures.





Re: Welding up Front Differential for Dirt Racing
Monday, May 15, 2006 10:44 PM
I had 205/60 15 all the way around. Today I put a 225/60 15 on the front passenger side. Not sure if I am going to leave the drivers side a 205 or get a 195. About half way through the corners the motor would rev and it seamed like I was spinning the tires. Will stagger alone help much or should I weld the spider gears also. I had the pressure 5 lbs below what they were max rated for.
Re: Welding up Front Differential for Dirt Racing
Tuesday, May 16, 2006 9:15 AM
best thing i can tell you is to ask the guys at the track for help, as much as you can


since there isnt alot of guys here dirt track racing


a welded diff should help out alot , but tire stagger will be more critical with a welded diff







Re: Welding up Front Differential for Dirt Racing
Tuesday, May 16, 2006 2:41 PM
They have a lot of people in the FWD class at the local tracks.Tri-state Area and Crawford country. (AR) Some famous NASCAR guys started out there. You can start for cheap.


--------------
Yea, ummmm. I used to have a J-body...

Re: Welding up Front Differential for Dirt Racing
Tuesday, May 16, 2006 9:30 PM
JASON BROWNING wrote:I had the pressure 5 lbs below what they were max rated for.


That right there is a big problem actually. Get that pressure way down in the front to increase the size of the contact patch below the front tires. I'd say to try running like 25-30 PSI front and see how you do w/ that. Depending on how you drive, you can try increasing PSI in the rear to give some more over-steer tendencies ("drift" around the corners).




F/S: 2005 KAWASAKI ZX-6R 636, 1107ish Miles, $7500 OBO
Re: Welding up Front Differential for Dirt Racing
Saturday, May 20, 2006 10:14 PM
1 st problem is you are running an auto... Second you dont want to weld the gears at all minus breaking things you need the outside tire to spin faster to help pull the car around the corner.

As for tire preasure on my 98 2.2 I run 235/60/14's on the front tubed at 10 and 12-14 lbs depending on track condition. Rear I run 215/60/15 at close to the same pressure. Granted you will break beads, you will maul tires, and you will turn a 90 dollar custom built 8" wide rim into a stop sign shaped object. TRUST me.

One question, are you manually shifting from 1st to second to hold the revs or are you just leaving it in 2nd/D?? I run mine all race long in 2nd and bounce of the rev limiter going into turns 1 and 3 (1/4 mile track) Now I could step the rims up to 15 but I can't get the wider tire in without buying more rims with larger offset.

Also I run new tire on the front. If you are running older tires they are harder and tend to not grip the track near as well... To the tune of about 3-4 seconds a lap difference.

If you are a low budge racer (which is fine) try picking up some wider tires that fit your rim from the local used tire joint and spray them with kerosine. That will help to soften the rubber. If ou can afford to buy yourself a new set of low dollar tires do it. I get my 14's for about 65 a piece and it is well worth it if you want to compete. Or in your case get better traction. (Also remember the fact it is dirt racing!)

There is a lot of other factors that come into play here but thoose are a few pointers to help out.
Re: Welding up Front Differential for Dirt Racing
Sunday, May 21, 2006 4:43 PM
Dave Smith wrote:1 st problem is you are running an auto... Second you dont want to weld the gears at all minus breaking things you need the outside tire to spin faster to help pull the car around the corner.


In my experience working on Ministocks, Hobbystocks, Streetstocks, Prostocks and Modifieds, automatics are fine with the lower divisions. At Volusia Speedway Park (1/2 mile clay D shaped oval, 12 deg of banking) in streetstocks we ran 6" of stagger on 28" and 29" tires with full spools. The mini stocks were running 4"-6" of stagger on on various 50-60 series 13" tires on their welded spider gears and a third of the feild was FWD.

Dave Smith wrote: As for tire preasure on my 98 2.2 I run 235/60/14's on the front tubed at 10 and 12-14 lbs depending on track condition. Rear I run 215/60/15 at close to the same pressure. Granted you will break beads, you will maul tires, and you will turn a 90 dollar custom built 8" wide rim into a stop sign shaped object. TRUST me.


We ran 12psi on the LR & 16-18psi on the RR with Hosier 4 & 6 Compound dirt tires. The tire compoound and belts are flexable enough to handle that low of a pressure and are designed for the tire to roll over to the outside tread. The minis are required to run DOT radials (no racing radials), and were running 20-22psi on the L and 22-24psi on the R on the drive tires. Street radials aren't as flexable as racing tires and don't have the side tread as a racing tire does. Running that low of a pressure, as you are ruinning, would cause the bead to break, cause the tire patch to cup and over heat the tire making it slick.

Dave Smith wrote: One question, are you manually shifting from 1st to second to hold the revs or are you just leaving it in 2nd/D?? I run mine all race long in 2nd and bounce of the rev limiter going into turns 1 and 3 (1/4 mile track) Now I could step the rims up to 15 but I can't get the wider tire in without buying more rims with larger offset.


On our Hobbystock we ran a TH350 w/ a manual valve body, shift kit and ratchet shifter. On restarts we would start in first and shift to second. Those that didn't have a manual valve body would just run in second, but just a tick slower on the restarts. We didn't have rev limiters, the motor would just run out of power around 6800-7000rpm, which was just past half way down the straights.

Dave Smith wrote: Also I run new tire on the front. If you are running older tires they are harder and tend to not grip the track near as well... To the tune of about 3-4 seconds a lap difference.


Same here, you want all the shoulder area to bite into the track with as you can and the freshest rubber to grip better.

Dave Smith wrote: If you are a low budge racer (which is fine) try picking up some wider tires that fit your rim from the local used tire joint and spray them with kerosine. That will help to soften the rubber. If ou can afford to buy yourself a new set of low dollar tires do it. I get my 14's for about 65 a piece and it is well worth it if you want to compete. Or in your case get better traction. (Also remember the fact it is dirt racing!)


Can't say anything here, we wern't allowed to chemically treat the tires in any way. If our tires were older and we needed fresh rubber, we would run a grinder over the tread, to get to the fresh rubber underneath. We only did this if the track had good bite and we couldn't get new tires.

Dave Smith wrote:There is a lot of other factors that come into play here but thoose are a few pointers to help out.


You might have noticed I only used past tense here, that's because after I got deployed for 17 months the owener/driver of the cars i was crew cheifing for couldn't find a good mechanic to fill in, so he got out. When I got back, I got stuck working weekends and haven't had the days off to work for anyone. If I do get weekends off anytime soon, there are a couple of dirt late model touring teams that are interested in me. That won't be as a the chief mechanic, but as general help, till I can learn their four link chasis systems they use.





Re: Welding up Front Differential for Dirt Racing
Sunday, May 21, 2006 8:40 PM
I run a 93 cavalier at my local dirt track wich is a semibanked 3/8 oval. Last year I had a similar problem with "no traction" in the turns and it turned out that the auto trans would slip in the middle of the turns. I went to a 5 speed man trans and that cured the problem. I thought about locking the diff but I have had no problem with traction in the turns with an open differential. There's a few guys at my speedway that seem to have locked differentials but to get in to the turns they have to hammer the e-brake and back it in to the turns to get it to go off of the turns nicely.


SK
Re: Welding up Front Differential for Dirt Racing
Tuesday, May 30, 2006 2:44 PM
The tire stagger helped out a lot the car was handeing alot better than the week before. I was doing pretty well in the feature untill the car started stalling. When this happens I loose power to everything. It sounds like it dies. All the gages, including the water temp fall to nothing and just pick back up after about a second or two. It does it over and over. It only does it after it gets warm. The last two laps of the heat race and about the 5th lap into the main. It died under caution and I had to stop on the track to restart it. Then had to go to the back of the pack. After that I took a corner a little too low and hit the dirt berm and rolled it over twice. The front is smashed up pretty good. It can be fixed with all new a-arms, rotors, spindels, tierods, and maybe axel shafts.

Would it be easier to get a new car and put my cage in it or replace all the things on my car. Thinking about finding one with a 5 speed. And maybe even a 2.4. Would the 2.4 be faster than the 2.2?
Re: Welding up Front Differential for Dirt Racing
Tuesday, May 30, 2006 2:59 PM
^ That ain't good to hear Is the front frame tweaked out from the roll?? If it survived, putting *new* (junkyard) parts in would be the quickest route. Will they still let you race after it's been rolled tho? The track I'm going to be racing at won't knowingly allow a vehicle to race after it's been rolled. Now if the driver/owner fixes it and changes the look, they might be able to get away with the rolled car.

With the engine issues tho, I'd look for a running 2.4 w/ 5spd... Hell, 3rd gen if they'll allow it. My Cav ia 2000 but it's 2200 auto




Re: Welding up Front Differential for Dirt Racing
Tuesday, May 30, 2006 4:25 PM
The track I went to would allow you to run the car again, if the cage is still intact and you pass tech. If the frame isn't tweeked, fixing it would be quickest and cheapest. If it is tweeked you could get a shop to straighten it, but it will never be the same. Handling would never be quite as consistant and consistancy is very important, especially learning to race.

I don't know about your track, but our's you're limited to no more than three valves per cylinder, which would rule out the 2.4L. If you can run a 4 valve motor, the 2.4L would be the way to go.

The TH125C is stronger than the Isuzu that comes in the Js, but the 5sp has more gears to chose from to get into you power band. An option for the 3 speed's gearing, if you need more gear, is to get the final drive (FD, differential) from a GM or Isuzu subcompact FWD with the 3 speed(such as the Pontiac LeMans, something with a 2.0L motor or smaller). You most likely have the 2.84:1 FD, the other cars will have either a 3.06:1 or 3.33:1 gearing, depending on the set-up from the factory.

Note though, the FD is in the deepest part of the tranny, it requires disassbling the entire tranny. If you up to it, or want to get it done, get the Alto-Red Eagle Master kit and rebuild the tranny for the utmost in strength. While your in there, you can weld the diff, or get a LSD Conversion such as the Phantom Grip or the Team Green(iF it's completed). With the PG, you would need part number 904-GOLD or GREEN(GREEN has the better springs for racing) or get Team Greens Springs, they'll fit. With the PG though, you will need to have a groove machined into the one of the blocks, for the axle retention clip, then assmeble the axle in the FD and assemble the internals around the axle shaft. Other than that, just follow their directions..

The Team Green LSD Coversion should be a direct fit and have even better springs than the PG. Note though tehy were still developing their LSD for the 3speed, last I knew.





Re: Welding up Front Differential for Dirt Racing
Wednesday, May 31, 2006 1:10 PM
I went back to the track last weekend and many people asked if I was going to be able to fix my car. So I guess they will allow it to run. The cage was not hurt at all.
Yes we can have up to 16 valves to I can run the 2.4.
Looking at the frame their maybe a very small wrinkle at the bottom where the indention is in the frame for tire clearance. Or whatever that spot is for. I had metal bolted in the frame so It appears that it is still straight.
We can run up to 16 valves so I would be able to run the 2.4. Will a 2.4 and Manual tranny bolt into my car. Or would a 2.4 bolt to my auto tranny? Does the 2.4 bolt to the TH125C, since it would be stronger?
Thanks for all the help...
Re: Welding up Front Differential for Dirt Racing
Wednesday, May 31, 2006 1:24 PM
The 2.2L OHV and 2.4L TC are two totally different motors, no the tranny wont bolt up. If you were to do a 2.4L TC conversion you would need the PCM and wiring harness, along with the motor and transmission. If you get one of the newer (2K+) motors they came with a Getrag, which is a little stronger 5 speed, but still not as durable as the 3 speed.





Re: Welding up Front Differential for Dirt Racing
Wednesday, January 17, 2007 7:46 PM
MadJack wrote:The 2.2L OHV and 2.4L TC are two totally different motors, no the tranny wont bolt up. If you were to do a 2.4L TC conversion you would need the PCM and wiring harness, along with the motor and transmission. If you get one of the newer (2K+) motors they came with a Getrag, which is a little stronger 5 speed, but still not as durable as the 3 speed.





um im no GM engineer but over at the Fiero forum the Th125 cant handle over like 200ft lbs of tourque.

The getrag has been PROVEN behind over 500ft lb SBC V8s Reliably! Stock!

and the isusu is in the same boat as the 125, you strip 2nd gear behind anything more than 200.

as far as i know the Th125 didnt really change much beetween fiero and cav.

could you be taking about the 4l60?

Re: Welding up Front Differential for Dirt Racing
Friday, January 19, 2007 12:54 AM
welding a diff is never really smart, read up on why. not a smart idea at all.
Re: Welding up Front Differential for Dirt Racing
Friday, January 19, 2007 6:32 AM
Scarab (Jersey Jay 1.8T) wrote:yeah, welding a fwd diff on a car that needs to turn is NOT a good idea. on a rwd car its completely different because you can spin the rear tires to turn (especially on dirt) but I think you'd be better getting an actual LSD for it. Since the front wheels have to turn to provide steering, if you weld the diff, the unequal loading on the gears and the weld between when you turn is going to break even the best welding job. How the heck do you dirt race a FWD anyway? understeer + lose surface = no fun

Believe it or not, a clay track when it starts to dry up hooks really good. I drove a 3spd auto neon last year and I could really drive the car deep into the corners when it started to dry. On a wet track the car wants to kick the back end out, its pretty much dead weight in the rear with a FWD so it helps in the corners. This is what it felt like when I drove, some people may say different but for me it felt like the car handled better in the dirt.


Also Jason I ran around 25-30 psi and that seamed to help. Some tracks in my area have a tire presure rule at like 45-50 to keep everyone the same in the compact classes.

Where do you run your car at??
Re: Welding up Front Differential for Dirt Racing
Thursday, February 15, 2007 12:18 PM
"Street tires arn't as flexible as racing tires" Who to the wha??? , not all racing tires are dirt racing tires. Street tires are far more flexible than racing tires by the norm, please don't categorize all racing tires as more flexible. Racing tires with the exception of those specifically designed dirt racing tires have much stiffer sidewalls so they don't roll over and can keep the bottom tread on the road as much as possible.

As Teamgreen said the LSD would be a much better option and I think theres currently a GP so you can get one for $150.00.


-Chris

Re: Welding up Front Differential for Dirt Racing
Monday, February 19, 2007 10:20 AM
IamRascal wrote:"Street tires arn't as flexible as racing tires" Who to the wha??? , not all racing tires are dirt racing tires. Street tires are far more flexible than racing tires by the norm, please don't categorize all racing tires as more flexible. Racing tires with the exception of those specifically designed dirt racing tires have much stiffer sidewalls so they don't roll over and can keep the bottom tread on the road as much as possible.

As Teamgreen said the LSD would be a much better option and I think theres currently a GP so you can get one for $150.00.
I think it was pretty obvious Jack was referring to dirt track tires...
Also, the Team Green 3spd hasn't been done yet because I still haven't pulled my diff for them...sorry guys.



fortune cookie say:
better a delay than a disaster.
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